I'm was getting the same error compiling a flex4 project. My project was set up to just run a bat file to build with the "No output, only run pre/post build commands" ticked and then launch a browser page running from my localhost running firefox.

The error occured in flashDevelop after the buildscripts have run and just before the launch of the project. No trace commands

It is now working but I'm not sure exactly if all of the steps made it work or just someMade sure the project file wasn't locked (using team foundation server for source control)Restarted flash developtried again no changeRemoved the bat script and let flash develop just compile the main fileTrace was workingAdded the bat file backStill workedAdded a break pointTicked No output...Still worked

Hi, I've exactly the same problem of "preecep" and with the same scenario: a message box appear in FlashDevelop IDE telling me: "Cannot find output file" , and the swf will play only after pressing OK button . Your solution worked for me yesterday when I was using 3.2.0 .Now I've downloaded 3.2.1 but unfortunately the problem still there… so I had to do your trick again and replace the tow files.Note that it will happen only when I choose "debug" from the "Select configuration" dropdown menu. It will not appear of course when I choose "release".

I had the same problem after updating, after doing the check - uncheck thing, compiling is working.But there is another problem.In the lower right corner , there is a status bar , that says:'Waiting for the flash player to connect to the debugger'And after a minute it pop up a alert window and says :" I/O Error occurred "whats up with that?

edit:I should also mention that I am working on a project that compiles through flash CS4 IDE. In previous version of FD I had no problems whatsoever.

Hi, sorry for using this same thread but I seem to have a similar problem with the difference that I'm compiling with Flex4 SDK. Here's the rundown of what happened:

I had FD3.1 installed. I had trace and debugging working.

Uninstalled it (settings included) and installed 3.2.1 RTM, just in case I also downloaded Flash Player Debugger, both ActiveX and Projector all latest versions available. Right now I don't have trace, debug and profiler doesn't kick also.

I do have the same "Waiting for Flash Player to connect to debugger" followed by a "I/O Error" dialog.

On the other hand the exact same project on my netbook (which I also updated FD following the exact same steps) is running perfectly. Difference is that desktop is Vista and netbook is XP.

I'm clueless about what is happening and any help would be awesome. Thanks!

I had the same problem as Vortix. To fix it, I found the debug player on my hard drive (it was in C:\Program Files\Adobe\Adobe Flash CS5\Players\Debug\FlashPlayerDebugger.exe) and ran it as an administrator; then I right-clicked a SWF in Explorer and told it to always open that type of file with FlashPlayerDebugger.exe; and finally I changed my FD Project Properties > Test Movie to "Play in external player".